Compressor blades of gas turbine engines are subject to foreign object damage (FOD). The nature of the damage could vary depending on the type of the foreign object: nicks, tears, dings and blade bending are common types of damages seen in the field. In order to make the damaged blades flight worthy again, the damaged areas of the airfoil are repaired in a well-defined fashion as outlined in repair and overhaul manuals. A typical blade repair scheme involves a cut out in the area of interest that is in the shape of an arc or “C” shape.
The typical blade repair scheme is not always successful because peak steady stress and peak vibratory stress locations may both coincide at the cutback radius. The peak vibratory stress may correspond to a resonance condition. This coincidence of vibratory and steady stress peaks is a concern from a durability stand point.
There is a need to improve such repair methods.